Count Unique Binary Search Trees | LeetCode 96 | C++, Java, Python | Catalan Number

[@OtterD-z3i]

Great job man, THANK YOU! This is the clearest explanation I have ever seen!

[@ayyappahemanth7134]

Man how did you get that idea of function ! That will take years for me to get that idea!. Kudos man! Great work!

[@KnowledgeCenter]

Thanks!

[@praveenj3112]

Really good Explanation . Can we solve this problem using Catalan number ? T(n)=2nCn/(n+1);

[@KnowledgeCenter]

Yes.

[@pmulchandani96]

This is awesome, I am always finding it difficult to derive the function in such kind of problems. It will be helpful if you can share that how you approach such kind of problems or is this something we can develop gradually by practicing. Any suggestions will be helpful. Thanks!

[@ayyappahemanth7134]

I just started for my final year computer science interview sir!. Can you make a video on how to proceed or plan of preparation . Please sir! Your videos are the most valuable to me right now!

[@KnowledgeCenter]

Try to focus on following aspects, see areas need improvement. You may already be good in some of these areas. * Pick a programming languages C++, Java, Python (or any other) - You should know it well. * Study OOPs concepts. * Data Structures and Algorithms (Big O analysis, Recursion, LinkedLists, Hashing, Search Trees, Sorting Algorithms - quick sort, merge sort, heap sort, Binary Search, Graph Algorithms, DP, Tries, Suffix Trees) * Low Level Design - Object-Oriented Analysis and Design * Operating Systems concepts - Multiprocessing, multithreading, deadlocks, scheduling etc. * Computer networks (Good to have) * Basics of Databases - RDBMS (Good to have) * High Level System Design (Nice to have, but not very critical) Note: For Graphs, it's not required to know all the algorithms in detail. A big chunk of problems will involve application of BFS or DFS. So, first have mastery over following, these should be good enough: * Graph Representation: adj. list and adj. matrix * BFS and DFS * Cycle Detection - Directed and Undirected cases * Topological Sort * Shortest Path - Dijkstra & Bellman Ford

[@ayyappahemanth7134]

@@KnowledgeCenter Thank you so much sir! Now my to-do list contains everyone you said! Hope I get a nice job during difficult times. Thanks for support in advance!

[@KnowledgeCenter]

All the Best.

[@KnowledgeCenter]

For Graphs, it's not required to know all the algorithms in detail. A big chunk of problems will involve application of BFS or DFS. So, first have mastery over following, these should be good enough: * Graph Representation: adj. list and adj. matrix * BFS and DFS * Cycle Detection - Directed and Undirected cases * Topological Sort * Shortest Path - Dijkstra & Bellman Ford

[@KnowledgeCenter]

@Ayyappa Hemanth: Added Some more info to TODO list.

[@kshitijsharma6471]

We can also solve using Catalan number (2*n)!/(n+1)!*(n)! Run time is almost same

[@KnowledgeCenter]

Right.

[@kameshkotwani]

lovely.

[@mukultaneja7243]

Thankyou sir for an amazing explanation. Please also tell.....how can we do it by recursion...?????

[@dineshchintu9779]

Thanks man (❁´◡`❁) ! The channel wil reach 100k soon !!

[@KnowledgeCenter]

Thanks for the best wishes.

[@chiragmongia733]

02:55- Can someone please explain this- why have we considered that for zero nodes, there would be 1 combination? Shouldn't it be 0?

[@KnowledgeCenter]

0 nodes is a possibility. It's not an impossible scenario. e.g., Left subtree or right subtree is Empty is a possible scenario.